Thermal contraction inital conditions

[tweekzilla]

Hi,

I'm trying to do a simple thermal contraction of a steel bar (1m length coe=15.7e-6) as a toy example. The idea is that the bar starts out at 300K (initial condition) and then has a boundary condition of 250K (one of the ends is also fixed). Now I would expect the bar to shrink 15.7e-6*50 = 0.79 mm but instead it shrinks 15.7e-6*250 = 3.9 mm. Is there a special way of setting up the initial conditions or is everything relative in some way?